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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:43 +0000 |
commit | 3e3e70d529d8c7d7c4d7bc4fefc9f109393b9245 (patch) | |
tree | daf049b282ab10e8c3d03e409b3cd84ff3f7690c /tests/ui/coinduction/canonicalization-rerun.rs | |
parent | Adding debian version 1.68.2+dfsg1-1. (diff) | |
download | rustc-3e3e70d529d8c7d7c4d7bc4fefc9f109393b9245.tar.xz rustc-3e3e70d529d8c7d7c4d7bc4fefc9f109393b9245.zip |
Merging upstream version 1.69.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/coinduction/canonicalization-rerun.rs')
-rw-r--r-- | tests/ui/coinduction/canonicalization-rerun.rs | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/tests/ui/coinduction/canonicalization-rerun.rs b/tests/ui/coinduction/canonicalization-rerun.rs new file mode 100644 index 000000000..b10ba3a81 --- /dev/null +++ b/tests/ui/coinduction/canonicalization-rerun.rs @@ -0,0 +1,54 @@ +// check-pass +// revisions: old new +//[new] compile-flags: -Ztrait-solver=next + +// If we use canonical goals during trait solving we have to reevaluate +// the root goal of a cycle until we hit a fixpoint. +// +// Here `main` has a goal `(?0, ?1): Trait` which is canonicalized to +// `exists<^0, ^1> (^0, ^1): Trait`. +// +// - `exists<^0, ^1> (^0, ^1): Trait` -instantiate-> `(?0, ?1): Trait` +// -`(?1, ?0): Trait` -canonicalize-> `exists<^0, ^1> (^0, ^1): Trait` +// - COINDUCTIVE CYCLE OK (no constraints) +// - `(): ConstrainToU32<?0>` -canonicalize-> `exists<^0> (): ConstrainToU32<^0>` +// - OK (^0 = u32 -apply-> ?0 = u32) +// - OK (?0 = u32 -canonicalize-> ^0 = u32) +// - coinductive cycle with provisional result != final result, rerun +// +// - `exists<^0, ^1> (^0, ^1): Trait` -instantiate-> `(?0, ?1): Trait` +// -`(?1, ?0): Trait` -canonicalize-> `exists<^0, ^1> (^0, ^1): Trait` +// - COINDUCTIVE CYCLE OK (^0 = u32 -apply-> ?1 = u32) +// - `(): ConstrainToU32<?0>` -canonicalize-> `exists<^0> (): ConstrainToU32<^0>` +// - OK (^0 = u32 -apply-> ?1 = u32) +// - OK (?0 = u32, ?1 = u32 -canonicalize-> ^0 = u32, ^1 = u32) +// - coinductive cycle with provisional result != final result, rerun +// +// - `exists<^0, ^1> (^0, ^1): Trait` -instantiate-> `(?0, ?1): Trait` +// -`(?1, ?0): Trait` -canonicalize-> `exists<^0, ^1> (^0, ^1): Trait` +// - COINDUCTIVE CYCLE OK (^0 = u32, ^1 = u32 -apply-> ?1 = u32, ?0 = u32) +// - `(): ConstrainToU32<?0>` -canonicalize-> `exists<^0> (): ConstrainToU32<^0>` +// - OK (^0 = u32 -apply-> ?1 = u32) +// - OK (?0 = u32, ?1 = u32 -canonicalize-> ^0 = u32, ^1 = u32) +// - coinductive cycle with provisional result == final result, DONE +#![feature(rustc_attrs)] +#[rustc_coinductive] +trait Trait {} + +impl<T, U> Trait for (T, U) +where + (U, T): Trait, + (): ConstrainToU32<T>, +{} + +trait ConstrainToU32<T> {} +impl ConstrainToU32<u32> for () {} + +fn impls_trait<T, U>() +where + (T, U): Trait, +{} + +fn main() { + impls_trait::<_, _>(); +} |